Enter the codes at the character select screen. To play as Mayhem press left,right,down,left,up,left,down,left,down. To plat as Assault press right,up,up,right,down,right,up,up. To play as Anil 8 press up,right,down,right,right,up,left,up. To play as Supervisor press down,right,down,up,right,down,left,down,up,right,up.